This application claims the benefit of the Korean Application No. P 2001-82699 filed on Dec. 21, 2001, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to device and method for removing contaminant particles from an optical disk.
2. Background of the Related Art
Recently, the development of a broad band multimedia environment inclusive of clearer video information and wide band audio signals, and the wide spread of PDAs and picture telephone, and the like require significant increase information capacity to be processed, handled and stored in those devices. Moreover, there have been ceaseless improvements of recording densities of magnetic information recording media, such as a small sized, and light weighted large capacity information storage devices, and hard discs used as a supplementary memory of a computer, and the like, and there have been various researches for increasing a recording density of an optical recording device, such as CD, and DVD.
Especially, the optical recording device has a system in which an optical disc, the recording medium, is in general detachable, to permit use of various contents, and make data storage, copy, and distribution easy.
The large capacity information storage device requires a high recording density, which in turn implies a small size of a data unit bit. Moreover, as one of pickup head fitted with a near-field optical system by using an aerodynamic buoyancy, which is one of pickup of a near-field optical system, a flying type slider head may be used for maintaining a gap to a recording film on a disk closer than a wavelength of an input laser beam.
For the maintenance of a near-field gap by means of the flying type slider structure, a functional structure of the slider which can secure a stable buoyancy in view of fluid dynamics is very important. Under this condition, if mounting/dismounting of the optical disk on/off a drive having the optical pickup fitted thereto is kept on, a surface of the optical disk is liable to be contaminated with an external contamination source of an external environment.
The contamination of a data bit part optical information is to be recorded thereon/reproduced therefrom may result in a situation the data is read wrongly, or the data can not be read, or new optical information is recorded wrongly, or is impossible to record. Particularly, in the case of a near-field optical recording device which has a very small gap between the recording surface of the optical disk and the optical pickup head, since the contamination of a data bit part, not only degrades the optical recording/reproducing performance of optical information, but also impedes the flying function of the optical pickup head seriously, the contamination of a data bit part is a major cause that drops reliability of recording/reproducing performance of entire optical recording device, significantly.
In a case of current optical information storage devices, such as CD and DVD which employ a far-field optical system, no particular contamination removal technique has been applied thereto. In a case of high density optical information storage devices under development, either a method is applied, in which the optical disk and the pickup drive are hermetically assembled such that the optical disk can not be dismounted for prevention of contamination, or a method is suggested, in which the optical disk is enclosed in a special cartridge which can reduce infiltration of contaminant, such as dusts, and the optical disk is mounted/dismounted to the optical pickup drive in a form of the cartridge, for maintaining the advantage of the optical disk.
However, it is very difficult to secure a long term reliability of optical information since a perfect cutting off infiltration of micro contaminants is very difficult, and a probability of contamination becomes very high as a number of times of use increases.
As the data recording density is increasing, a structure of the optical disk is developing into a form an optical recording layer required for recording and reproduction is formed on a surface of the optical disk a beam is incident thereto, and a size of an optical information mark to be recorded/reproduced is also reduced. Particularly, the feature of mounting/dismounting of the optical disk, that permits the optical disk to be carried more conveniently, distribute information more easily, and cost lower, than a magnetic recording device, makes the contamination from an external environment unavoidable.
This situation mounts a hazard of malfunction of the information storage device caused by a surface contamination of the optical disk higher than the optical disk of a current far-field optical system.
Accordingly, the present invention is directed to device and method for removing contaminant particles from an optical disk that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide device and method for removing contaminant particles from an optical disk, which can enhance reliability of information recording/reproduction on/from an optical disk.
Another object of the present invention is to provide device and method for removing contaminant particles from an optical disk, which can remove contaminant particles from a surface of an optical disk with easy.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the contaminant particles on a surface of an optical disk required for recording, reproduction and flying of an optical pickup head are driven in a particular direction, and removed therefrom by electrophoresis or dielectricphoresis.
Preferably, a plurality of conductive lines of metal, or the like are buried in a part except a region optical information is recoded thereto/reproduced therefrom. The conductive lines have predetermined waveforms applied thereto, owing to which micro particles, a source of contamination of the optical disk, is driven in a desired direction.
Accordingly, alike an optical disk in a near-field optical system, if a recording layer is formed in a substrate surface region, the present invention improves a reliability of an optical recording device having a micro gap between the recording layer and the optical pickup head.
Moreover, the present invention can be used very favorably in removing, or reducing contamination of the optical disk of an optical recording device employing a far-field optical system, such as CD, DVD, and HDVDR, or an optical disk of a near-field optical recording device employing an SIL optical system.
In one aspect of the present invention, there is provided a device for removing contaminant particles from an optical disk having an optical disk substrate, a reflective layer on the disk substrate, a first insulating layer on the reflective layer, a recording layer on the first insulating layer for recording/reproducing a data thereon/therefrom, and a second insulating layer on the recording layer, the device including an electrode pattern of a plurality of concentric circles on the optical disk except the recording layer, a third insulating layer on the electrode pattern to expose a region of the electrode pattern, and a number of connection electrodes in contact with the exposed electrode pattern for applying dust collecting voltages to the electrode pattern.
Preferably, the connecting electrodes are in contact with electrode patterns at predetermined fixed intervals, and the number of the connection electrodes are two or more than two.
Preferably, the connection electrodes are perpendicular to the electrode pattern of the optical disk, further includes pads in contact with the connecting electrodes, and the pads are in a hub part at a central part of the optical disk.
The number of connection electrodes apply AC signals of different phases to adjacent electrode patterns as dust collecting drive voltages. The connection electrodes include a predetermined number of independent power sources for supplying the dust collecting drive voltages to the predetermined number of connection electrodes.
Preferably, the device for removing: contaminant particles further includes an edge triggered flipflop for providing AC signals of predetermined frequencies in response to the same clock generating signals, and a voltage amplifier for receiving and amplifying, the AC signals from the edge triggered flipflop for providing the dust collecting drive voltages to the connection electrodes.
Preferably, the device for removing contaminant particles further includes a wiper fitted to a part of the optical disk for removing particles collected to a predetermined region of the optical disk from the optical disk.
In another aspect of the present invention, there is provided a method for removing a contaminant particle from an optical disk, comprising the step of electrically collecting the contaminant particle from a surface of an optical disc in a direction of a hub or an edge of the disc by applying driving voltages to an electrode pattern of the optical disc through connection electrodes, wherein the electrode pattern electrically connected to the connection electrode and dielectrically connected to a recording layer of the disc is concentrically formed on the recording layer.
Preferably, the connection electrode applies AC signals having different phases for collecting the contaminant particles, and the AC signals are any one of square wave, sinusoidal wave, and triangular wave.
Preferably, the dust collecting drive voltage has a retarded phase depending on a collecting direction of the contaminant particle, an amplitude fixed based on intervals of the electrodes, and a duty ratio of the driving voltage is fixed based on electrical characteristics of the contaminant particles.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.